Meltdown variants.
The Meltdown attack [1]} bypasses implicit memory permission
checks within the CPU during transient execution.
Unlike Spectre, Meltdown does not rely on executing instructions in the
victim domain, so it cannot be mitigated purely by changes to the victim's
code.
Foreshadow [2]} and microarchitectural data sampling
(MDS) [3]}, [4]} demonstrate that transient
faults and microcode assists can still leak data from
other security domains, even on CPUs that are resistant to Meltdown.
Researchers have extensively evaluated these Meltdown-style attacks leading to new vulnerabilities [5]}, [6]}, [7]}, but most recent Intel CPUs have hardware-level mitigations for all these vulnerabilities in the form of microcode patches or proprietary hardware fixes [8]}.
